Study aims for comparison of trabeculectomy and canaloplasty, in order to find out if one operation is superior to the other. Both procedures are performed in patients with medically uncontrolled open-angle glaucoma. Canaloplasty is a recently newly introduced procedure, which showed encouraging results without antimetabolite usage intra- and postoperatively. Purpose of the study is to compare both surgeries concerning success rate, intraocular pressure, medication and complications. So far there is no comparison of the standard procedure trabeculectomy and the new approach, canaloplasty available.